1. Field of Invention
The present invention relates to a semiconductor apparatus substrate, a semiconductor apparatus, a method of manufacturing thereof and an electronic apparatus.
2. Description of Related Art
Bare-chip mounting methods may be ideal methods to achieve further miniaturization of semiconductor apparatuses. However, because quality control and handling of semiconductor apparatuses made by such methods are difficult, semiconductor apparatuses are provided in the form of packages in order to counter such difficulties. One example of such packages is a BGA (Ball Grid Array) type package in which a semiconductor chip is connected to a substrate having wiring patterns, and external terminals are formed on the wiring patterns. Japanese laid-open patent application HEI 8-107161 describes a package different from the BGA type package for a semiconductor apparatus using a substrate in which external terminals are formed on a peripheral edge area of the substrate.
The semiconductor apparatuses described above need to change wiring patterns depending on the size of semiconductor chips mounted thereon when substrates are formed to have a uniform size. For example, when the size of a substrate is similar to the size of a semiconductor chip, wiring patterns are formed adjacent peripheral areas of the substrate. However, when the size of a semiconductor chip is substantially smaller than the size of a substrate, wiring patterns are drawn in toward a central area of the substrate.
When a relatively small semiconductor chip is mounted on a substrate having wiring patterns formed adjacent the peripheral area of the substrate, longer bonding wires must be used. The wires are often made of gold. As a result, the cost increases, and there is a possibility that the wires are pushed and cut by sealing resin when resin-sealing process is performed.
Consequently, for semiconductor apparatuses using the conventional substrates, the substrates cannot be provided with common wire patterns. Several different wire patterns are required depending on the size of semiconductor chips, and therefore the demand for increased productivity and reduced costs cannot be met.
The present invention provides solutions to these problems, and it is an object of the present invention to provide a semiconductor apparatus substrate, a semiconductor apparatus and a method of manufacturing thereof and an electronic apparatus that achieve excellent productivity and cost reduction.
In accordance with the present invention, a substrate for a semiconductor apparatus for mounting a semiconductor device thereon to form a semiconductor apparatus comprises a substrate member having a mounting surface for mounting the semiconductor device, a plurality of leads supported by the mounting surface of the substrate member for wire-bonding to the semiconductor device, and a conduction section electrically connected to each of the leads to thereby form at least a part of an external terminal, wherein at least one of the leads has a portion located under the semiconductor device and a remaining portion not located under the semiconductor device depending on the size of the semiconductor device.
In accordance with the present invention, a semiconductor device is positioned over the leads and mounted on the substrate member. As a result, when semiconductor devices having different sizes are mounted on the substrate members, only the length of portions of the leads located below the semiconductor devices differs. Accordingly, substrates having a common size can be used for semiconductor devices of different sizes, and therefore the cost is reduced. Also, the leads located below the semiconductor device are close to the semiconductor device, and accordingly shorter wires can be used, so that the wires are less likely to cut when the wires are sealed in resin.
The conduction section may be formed in a manner that the conduction section extends from a side surface of the substrate member to a surface opposite of the mounting surface for mounting the semiconductor device.
As a result, the conduction section itself can be used as an external terminal.
The substrate member has at least one through-hole formed for each of the leads, and the conduction section is formed on the surface opposite to the mounting surface of the substrate member and may be electrically connected to each of the leads through the through-hole.
As a result, the conduction section is formed on the surface of the substrate member that is not provided with the semiconductor device, and external terminals can be formed on the entire area of this surface, with the result that a face-mount type semiconductor apparatus is manufactured.
Substrate through-holes are formed in the substrate member to communicate with a lead through-hole defined in each of the leads, and each of the leads has at least one wide region for forming the lead through-hole wherein the plurality of leads are disposed such that the wide regions thereof may be positioned in a staggered fashion.
Because the wide regions of the leads are disposed in a staggered fashion, many leads can be disposed with high density.
The plurality of leads extend radially from a peripheral area toward a central area of the substrate member.
Because the leads are radially disposed, many leads can be disposed with high density.
Those of the plurality of leads that extend to corner portions of the semiconductor device to be mounted may protrude toward the central area of the substrate compared to the other of the plurality of leads.
Generally, a semiconductor device has a rectangular external shape, and electrodes are disposed along edges thereof. Therefore, the electrodes at respective corners are separated relatively far from the edges. As a result, the leads are separated most from the electrodes at the respective corners. Also, when the leads are radially disposed, not all of the leads can be extended to the central area of the substrate member.
By using the structure described above, those of the leads disposed at positions corresponding to the corners at which the leads are most separated from the edges are protruded toward the central area farther than other ones of the leads. As a result, the distance between the leads and the electrodes is generally equalized.
The substrate for a semiconductor apparatus is provided with a substrate through-hole for each of the leads, and the substrate through-hole communicates with the lead through-hole defined in each of the leads in the peripheral area of the substrate member.
The leads need to have a greater width to provide a lead through-hole in the lead. When the leads are radially disposed, the width of the leads can be made greater in the peripheral areas of the substrate member. Therefore, lead through-holes may be provided in the leads adjacent to the peripheral areas of the substrate member. As a result, the leads are disposed with high density without a hindrance.
A semiconductor apparatus in accordance with the present invention includes a semiconductor device having a plurality of electrodes and a substrate defining a mounting surface for mounting the semiconductor device. The substrate has a plurality of leads supported by the mounting surface, and a conduction section electrically connected to each of the leads to thereby form at least a part of an external terminal. The semiconductor device is mounted on a lead-forming surface of the substrate on which the leads are formed. At least one of the leads has a portion located under the semiconductor device and the remaining portion not located under the semiconductor device, and the electrodes of the semiconductor device are wire-bonded to the respective leads.
In accordance with the present invention, a semiconductor device is positioned above the leads and mounted on the substrate. As a result, when semiconductor devices having different sizes are used, only the length of portions of the leads located below the semiconductor devices differs. Accordingly, substrates having a common size can be used without regard to the size of semiconductor devices. As a result, the cost is reduced.
Also, the leads located below the semiconductor device are positioned close to the semiconductor device and therefore shorter wires can be used, so that the wires are less likely to be cut when the wires are sealed in resin.
The semiconductor device may be mounted on the substrate on a surface opposite to the surface having the electrodes formed thereon. Each of the electrodes of the semiconductor device is connected to each of the leads by a wire, and the at least one lead having one portion located under the semiconductor device is connected to the wire at a location not under the semiconductor device.
As a result, when semiconductor devices having different sizes are used, only wire bonding positions with respect to the leads change, and therefore, substrates having a common size can be used without regard to the size of semiconductor devices.
An insulation member may be provided between the semiconductor device and the substrate.
The insulation member provides insulation between the leads and the semiconductor chip.
Any one of the semiconductor apparatus substrates described above may be used as the substrate.
The conduction section is formed on a surface opposite of the lead-forming surface of the substrate. The substrate includes a substrate through-hole for each of the conduction sections, each of the conduction sections electrically connected to each of the leads through the through-hole. A plurality of the conduction sections are disposed at predetermined pitches, and the external terminals are formed only on at least every other conduction section.
As a result, the pitch of the external terminals are changes.
A method for manufacturing a semiconductor apparatus in accordance with the present invention includes:
preparing a substrate having a plurality of leads supported by one surface thereof and a conduction section electrically connected to each of the leads to thereby form at least a part of an external terminal;
mounting a semiconductor device on a part of at least one of the leads to thereby attach the semiconductor device to the substrate; and
wire-bonding electrodes of the semiconductor device to the leads.
In accordance with the present invention, a semiconductor device is positioned above the leads and mounted on the substrate. As a result, when semiconductor devices having different sizes are used, only the length of portions of the leads located below the semiconductor device changes. Accordingly, substrates having a common size can be used without regard to the size of semiconductor devices. As a result, the cost is reduced.
In this method, the semiconductor device is mounted on an opposite surface of the substrate opposite to the surface having the electrodes. The electrodes of the semiconductor device are connected to leads by wires. The leads have portions located under the semiconductor device that are connected to the electrodes by the wires at locations not under the semiconductor device.
As a result, when semiconductor devices having different sizes are used, only wire bonding positions with respect to the leads change, and therefore, substrates having a common size can be used without regard to the size of semiconductor devices.
An electronic apparatus in accordance with the present invention has a circuit substrate provided with the semiconductor apparatus manufactured according to one of the methods described above.